I don't know why people think "Blaine" was a fan mistranslation. If anything, "Brain" was an SENA mistranslation. The "l" is replace with "r" in Japanese-spoken English words because that's the style. If the original was "Bu-rain-u" or something like that, then it would be natural that the English translation was "Blaine". Again, "Brain" was probably another SENA translation error (right Roxas).

Maybe they can be both correct translations, because in japanese Blaine and Brain sound the same? I don't know japanese, I'm just guessing, but if this is the case then there's no mistake, just a choice they made.

Now, YouTube user crazycatz00 has found, while looking through the game data, that the Japanese version of the game also includes full English text, including text cutscenes and in-game dialog boxes. This text can't be accessed normally, but has been revealed to be stored on the game disc through hacking. Thanks to KH13 user jadentheman, you can watch the video of this being demonstrated below.

Update: The same YouTube user has uploaded two new videos showing that the cutscenes added in the Final Mix reissues are in fact fully translated with English voicing acting and that Kingdom Hearts Birth by Sleep Final Mix is also fully in English. You can also view these videos below.

Update 2: Thanks to YouTube user Sora6645 we now have a recording of the final cutscene in Kingdom Hearts Birth by Sleep Final Mix, which features the infamous Birth by Sleep -Volume 2- at the end. Now fully in English, you can view it below.

FM cutscenes are real time IIRC. Only thing pre-rendered in KH2 are the opening/ending FMVs and the cutscene right before 1000 heartless war. Recording in english for 2.5 was done months ago so there might be a chance the voices are in there. Gonna need to check on that

The English voice acting being in the game is nothing new. The original KH2FM already had both English and Japanese voice acting already in the game. Japanese was simply available through the theater mode and it was confirmed on stream that Japanese 2.5 can already access the English voices in theater without any hacking at all. If the FM exclusive cutscenes ARE dubbed in English, you can easily figure it out by going into the theater and putting the settings to English.

FM cutscenes are real time IIRC. Only thing pre-rendered in KH2 are the opening/ending FMVs and the cutscene right before 1000 heartless war. Recording in english for 2.5 was done months ago so there might be a chance the voices are in there. Gonna need to check on that

Now, Youtube user crazycatz00 has found, while looking through the game data, that the Japanese version of the game also includes full English text, including text cutscenes and in-game dialog boxes. This text can't be accessed normally, but has been revealed to be stored on the game disc through hacking. Thanks to KH13 user jadentheman, you can watch the video of this being demonstrated below.

I wonder why they are giving everyone else the game 2 months later. Maybe 1 month I'd understand. Oh well. I wouldn't have much time to play it with school and all.
Now maybe Bizkit could play the certain cutscenes in a livestream...

I wonder why they are giving everyone else the game 2 months later. Maybe 1 month I'd understand. Oh well. I wouldn't have much time to play it with school and all. Now maybe Bizkit could play the certain cutscenes in a livestream...

Well Square can fix stuff that was messed up in the Japanese version or, rarely, add stuff